The present invention relates to automotive vehicle test equipment. In particular, the invention relates to a controller for an automotive vehicle test system.
Automotive vehicle test equipment is used to measure various parameters which relate to automotive vehicles. For example, automotive vehicle test equipment can test parameters such as vehicle exhaust emissions, wheel alignment or engine operation.
In some situations, the automotive vehicle test equipment must be capable of being interrogated from a remote site. This is typically done using telephone communications. Many states now require automotive vehicle certification of exhaust gas emissions. Automotive vehicles are tested at remote locations throughout the day and test results and owner information are stored in the automotive vehicle test system. Subsequently, the stored information is transferred to a central location for review by the appropriate state officials. Typically, this transfer process takes place during off hours when telephone rates are less and when the test equipment is not in use to test automotive vehicles.
The automotive vehicle test equipment must constantly monitor a telephone line for receipt of an interrogation signal from the central location. If the equipment is turned off by an operator, the automotive vehicle test system will be unable to respond to the interrogation request when it is received over the telephone line.
If the automotive vehicle test equipment is continually left turned on, the system will waste power and the lifespan of the components in the system will be significantly reduced. One possible solution is to provide only a brief time window during which an interrogation command from the central site may be received. This is both inconvenient and impractical. This technique requires an operator to insure that the system is turned on at the beginning of the time window and subsequently turned off, after the end of the time window. Furthermore, if the central location is delayed in sending the interrogation request to the automotive vehicle test equipment, the time window will pass by and it will be impossible for the central location to collect stored information from the automotive vehicle test system.